Energy detect with auto pair select

ABSTRACT

Energy detect with auto pair select. The present invention is operable without ‘a priori’ knowledge of the pairs&#39; connectivity. In addition, the present invention is operable within systems performing automatic detection of connectivity in systems that employ the Ethernet based media dependent interface crossover (MDIX). Where there has been some cross-over of pairs within the system, a situation not uncommon in many networks, the present invention is operable to perform energy management even without having any knowledge of the pair connectivity. Knowledge relating to the energy of multiple pairs is used to perform energy detect and management. A state machine operates in performing the analysis of the energy using a qualified energy level. The present invention is also operable within systems that do not employ auto-negotiation. In systems where auto-negotiation is performed, the present invention is performed before the auto-negotiation to determine if an operable partner exists within the network.

BACKGROUND

[0001] 1. Technical Field

[0002] The invention relates generally to energy detect and auto powerdown devices; and, more particularly, it relates to a system and methodoperable to perform energy detection and auto pair selection within adevice that is operable to perform power savings.

[0003] 2. Related Art

[0004] Prior art energy detection systems depend intrinsically upon apriori knowledge of the connectivity of wires, and pairs of wires,within their respective systems to perform energy savings. That is tosay, a definitive knowledge of the connectivity to the system isrequired to perform proper power savings functionality. The operation ofsuch systems becomes increasingly difficult when the wires have beenimproperly connected. In come cases, the system will fail to function atall. That is to say, when there is no knowledge of the connectivity,there is an inability within the system to perform proper powermanagement.

[0005] Traditionally, networks were often designed to include a hub anda number of devices connected to the hub. In this situation, there is noproblem with connectivity of pairs of wires, as the hub performs thechange over of the pairs within the hub itself. However, as networktopologies have grown to include a number of devices besides thistraditional hub and spoke type of interconnection, then device-deviceconnectivity (where neither of the devices are hubs) can be problematicto the operation of the energy and power management system. Oftentimes across-over connection is inserted, for example in the case of Ethernet,to accommodate the fact that the send and receive paths differ in thiscontext compared to a device-hub connection context.

[0006] Further limitations and disadvantages of conventional andtraditional systems will become apparent to one of skill in the artthrough comparison of such systems with the invention as set forth inthe remainder of the present application with reference to the drawings.

SUMMARY OF THE INVENTION

[0007] The present invention provides, for the first time, a solutionthat is operable in conjunction with automatic media dependent interfacecrossover (MDIX). Auto MDIX is commonly referred to in Ethernet relatedtechnology. Prior art technologies inherently relied upon definitiveknowledge about which wire pair is the receive pair in order to performproper energy management. The present invention significantly increasesthe usefulness of an auto power down circuitry, as it may now be used inconjunction with auto MDIX.

[0008] Single wire, wire pair, and other connectivity schemes may allbenefit from various aspects of the present invention. As link pulsesare sent along wires, to determine connectivity within the system, theenergy associated with the link pulse is suppressed in performing autopower down operation and energy management.

[0009] The present invention is operable to perform proper function ofany energy detect and power down circuitry without having any knowledgeof which pair is the transmit pair and which pair is the receive pair.From certain perspectives, the present invention considers energydetection information from both the transmit and receive wire pairs.Then, the present invention is operable to determine the presence of alink partner regardless of whether the wiring was installed properly ornot.

[0010] Part of an auto power down method, performed in accordance withcertain aspects of the present invention, involves periodicallytransmitting link pulses on one of the transceiver's wire pairs in orderto potentially awaken the link partner. This operation may be performedsequentially across a number of the wire pairs as well. Then, an autopower down select circuitry is operable to cease monitoring of the wirepair on which the link pulses are sent; this is to ensure that a falsedetection of energy is not made by the device's own generated linkpulse. From certain perspectives, the energy that is associated withlink pulse that is transmitted may be subtracted, actually or logically,from the circuitry that performs the energy management. Variousembodiments are described below that perform the proper handlingoperation of the energy that is associated with a transmitted link pulseon one or more wire pairs.

[0011] The above-referenced description of the summary of the inventioncaptures some, but not all, of the various aspects of the presentinvention. The claims are directed to some other of the various otherembodiments of the subject matter towards which the present invention isdirected. In addition, other aspects, advantages and novel features ofthe invention will become apparent from the following detaileddescription of the invention when considered in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] A better understanding of the invention can be obtained when thefollowing detailed description of various exemplary embodiments isconsidered in conjunction with the following drawings.

[0013]FIG. 1 is a system diagram illustrating an embodiment of an energydetect with auto pair select system that is built in accordance withcertain aspects of the present invention.

[0014]FIG. 2 is a system diagram illustrating another embodiment of anenergy detect with auto pair select system that is built in accordancewith certain aspects of the present invention.

[0015]FIG. 3 is a system diagram illustrating another embodiment of anenergy detect with auto pair select system that is built in accordancewith certain aspects of the present invention.

[0016]FIG. 4 is a system diagram illustrating another embodiment of anenergy detect with auto pair select system that is built in accordancewith certain aspects of the present invention.

[0017]FIG. 5 is a system diagram illustrating another embodiment of anenergy detect with auto pair select system that is built in accordancewith certain aspects of the present invention.

[0018]FIG. 6 is a state diagram illustrating an embodiment of operationof an energy detect with auto pair select state machine that isperformed in accordance with certain aspects of the present invention.

[0019]FIG. 7 is a functional block diagram illustrating an embodiment ofan energy detect with auto pair select method that is performed inaccordance with certain aspects of the present invention.

[0020]FIG. 8 is a functional block diagram illustrating anotherembodiment of an energy detect with auto pair select method that isperformed in accordance with certain aspects of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0021] In various embodiments of the present invention, the terminologyof pairs is used. Those persons having skill in the art will appreciatethat single wire connectivity is also included within the scope andspirit of the invention. The pair embodiment will be understood by thosepersons having skill in the art, given the large number of commercialtypes of wires that employ pair wires, twisted pairs, and so on.However, the present invention is also operable within embodiments thatemploy single wire connectivity throughout.

[0022] An energy detect circuitry, that is operable to perform autopower down, monitors an attached wire. This energy detect circuitrydetermines if any incoming signal, or any energy, is present on the wirethat will signal that a link partner is attached to the other end of thewire. When there is no wire attached to the other end, or no linkpartner attached to the other end of a wire connected to a device, thenno energy will be present on the wire, and the energy detect circuitry(the detector) will indicate this condition. A state machine, that isalso described in various embodiments, is operable to recognize variousforms of transmission. One application area is the Ethernet context. Thestate machine can specifically recognize 10Base-T link pulses, 10Base-Tpackets, 100Base-T link, and auto-negotiation link pulse bursts.

[0023] The present invention is at least one operable within systemsthat employ Ethernet based media dependent interface crossover (MDIX).Previous systems experienced difficulty when this additionalfunctionality was introduced. An auto MDIX solution automaticallycompensated for any improperly installed cable pair(s). The auto MDIXsolution is introduced to allow proper functionality even when cable hasnot been installed properly, and there is the undesirable crossover ofwires. Ethernet employs certain conventions to ensure that the receiveand transmit wire pair(s) are not swapped when the cable is installed ina particular site. Prior art energy detect/power down circuitry reliedsolely upon energy being detected on the receive wire pair(s). The autoMDIX functionality is implemented into a number of transceivers. Thepresent invention performs an elegant modification to ensure properfunctionality of any energy detect/power down circuitry even when autoMDIX is implemented.

[0024] From certain perspectives, a new element is added to atransceiver-operable device. The device may be a chip, a board havingdiscrete components or chip-sets, or any other device having logic andoperational configure-ability. The present invention is adaptable withinBCM5411 and BCM5421 transceiver chips designed by Broadcom Corporation.The present invention is operable to perform proper function of anyenergy detect and power down circuitry without having any knowledge ofwhich pair is the transmit pair and which pair is the receive pair. Fromcertain perspectives, the present invention considers energy detectioninformation from both the transmit and receive wire pairs. Then, thepresent invention is operable to determine the presence of a linkpartner regardless of whether the wiring was installed properly or not.

[0025] This new element, added to the transceiver-operable device, issometimes referred to an energy detect with auto pair select. When atransceiver is trying to determine if there is a link partner attached,then the present invention is operable to perform monitoring of all ofthe wire pairs that are connected to the transceiver. This isparticularly helpful when auto MDIX is employed, and there is noknowledge of the connectivity of the pairs. Here, with no knowledge ofwhich is the transmit pair and which is the receive pair, then thepresent invention is operable to monitor both pairs.

[0026] Part of an auto power down method, performed in accordance withcertain aspects of the present invention, involves periodicallytransmitting link pulses on one of the transceiver's wire pairs in orderto potentially awaken the link partner. This operation may be performedsequentially across a number of the wire pairs as well. Then, an autopower down select circuitry is operable to cease monitoring of the wirepair on which the link pulses are sent; this is to ensure that a falsedetection of energy is not made by the device's own generated linkpulse. From certain perspectives, the energy that is associated with alink pulse that is transmitted may be subtracted, actually or logically,from the circuitry that performs the energy management. Variousembodiments are described below that perform the proper handlingoperation of the energy that is associated with a transmitted link pulseon one or more wire pairs.

[0027] The present invention provides, for the first time, a solutionthat is operable in conjunction with auto MDIX. Prior art technologiesinherently relied upon definitive knowledge about which wire pair is thereceive pair in order to perform proper energy management. The presentinvention significantly increases the usefulness of an auto power downcircuitry, as it may now be used in conjunction with auto MDIX.

[0028]FIG. 1 is a system diagram illustrating an embodiment of an energydetect with auto pair select system 100 that is built in accordance withcertain aspects of the present invention. A device 110 and a device 120are communicatively coupled via an n pair interconnect 130. The n pairinterconnect 130 includes an indefinite number of pairs shown as a pair#1 131, . . . , and a pair #n 139. The device 110 includes an energydetect circuitry 112, a state machine (logic circuitry) 114 and a powerdown/energy saving circuitry 116. The functionality offered by the powerdown/energy saving circuitry 116 is sometimes referred to as auto powerdown functionality in various embodiments. The pair energies of at leastone of the pairs within the n pair interconnect 130 is provided to theenergy detect circuitry 112. Then, based on the energy information ofthe pairs that are provided to the energy detect circuitry 112, thestate machine 114 identifies the connectivity of the devices that areconnected to the device 110. When no device is connected to the device110, the power down/energy saving circuitry 116 is operable to performthe auto powering down of the device 110 to conserve energy.

[0029] The device 120 need not necessarily have the same circuitry andneed not necessarily be operable to perform the same functionality asthe device 110. That is to say, even if the device 120 is not able toperform such energy savings/energy power down functionality, it will notimpede such functionality on the device 110. Certain aspects of thepresent invention are operable to be backward compatible, from certainperspectives, into systems that have a number of devices that areincapable of performing the energy detect with auto pair selectfunctionality. In addition, devices within the network may also beupgraded to include the functionality offered by certain aspects of thepresent invention without entering any deleterious effects into other ofthe devices within the network.

[0030]FIG. 2 is a system diagram illustrating another embodiment of anenergy detect with auto pair select system 200 that is built inaccordance with certain aspects of the present invention. A device 210is operable to perform the functionality of energy detect with auto pairselection 212. The present invention is capable to perform thisfunctionality without requiring any ‘a priori’ knowledge of the receiveand transmit pairs 214.

[0031] For example, the device 210 is operable when connected to one ormore of a nonenergized device 220, to an energized device 230, or evenwhen there is a pair that is connected to no device at all. The pairsare shown as twisted pairs in this illustration. If desired, auto MDIXfunctionality may be performed along one or more of the pairscommunicatively coupled to the device 210. In addition, one or more ofthe device to which the device 210 is communicatively coupled may alsoperform auto MDIX.

[0032] When the device 210 is communicatively coupled to an energizeddevice, such as the energized device 230, then the device 210 willrecognize this and will remain powered up for full operation. Then, ifthe energized device 230 ever becomes non-energized, the device 210 willrecognize this event and will move into an auto power down sequence.There may also be situations where a pair is connected to the device210, but no other device is communicatively coupled to the other end ofthe pair. Here, the device 210 will be operable to determine that noother device is there, and will perform auto power down functionalitythereafter.

[0033] It is also noted that the present invention is operable toperform within systems and networks where other of the devices withinthese networks and systems may or may not employ auto MDIXfunctionality. As mentioned above, the present invention offers a degreeof backward compatibility here.

[0034]FIG. 3 is a system diagram illustrating another embodiment of anenergy detect with auto pair select system 300 that is built inaccordance with certain aspects of the present invention. The energy ofan indefinite number of pairs, shown as energy pair 1, . . . , andenergy pair n is fed to an energy summing circuitry 310. From the energysumming circuitry 310, a total energy of the pair(s) is provided to atransmit energy subtraction circuitry 320. It is noted that the presentinvention is operable to perform this functionality within systems whereonly a single wire pair is used, as well as an indefinite number of wirepairs as well. Here, in the energy subtraction circuitry 320, a linkpulse energy subtraction circuitry 322 subtracts the transmitted linkenergy. A qualified energy of the pair(s) is provided from the energysubtraction circuitry 320 to a state machine (logic circuitry) 330. Thestate machine (logic circuitry) 330 determines knowledge of theconnectivity of the system.

[0035]FIG. 4 is a system diagram illustrating another embodiment of anenergy detect with auto pair select system 400 that is built inaccordance with certain aspects of the present invention. The raw energysignals, that may be produced by sets of comparators in an analog frontend of a transceiver, are first combined together using an OR gate. Anynumber of energy pairs may be combined in the OR gate. Then, the outputof the OR gate is fed to an AND gate, where it is combined with alogical signal associated with the energy being transmitted via a linkpulse. The result is such that it is suppressed during and some periodafter the transceiver transmits a link pulse. A qualified energy signalis then fed to a remaining portion of the auto power down circuitry. Astate machine 414, employing logic circuitry, is operable to provideinformation regarding the connectivity of the system.

[0036]FIG. 5 is a system diagram illustrating another embodiment of anenergy detect with auto pair select system 500 that is built inaccordance with certain aspects of the present invention. An energydetect with auto pair select device 510 is communicatively coupled toany number of other devices via twisted pair(s). The other devices areshown as device #1 521, . . . , and device #n 529. The energy detectwith auto pair select device 510 is operable to perform energy detectwith auto pair select functionality 512, as well as auto MDIXfunctionality 521, and auto power down functionality 522. The energydetect with auto pair select functionality 512 enables the energy detectwith auto pair select device 510 to perform the auto MDIX functionality521 and the auto power down functionality 522 to operate in conjunction.Within prior art systems, any auto MDIX functionality necessitateddefinitive knowledge of the connectivity of the wire pairs. Here, theenergy detect with auto pair select functionality 512, as offered by thepresent invention, enables the proper functionality of the system.

[0037]FIG. 6 is a state diagram illustrating an embodiment of operationof an energy detect with auto pair select state machine 600 that isperformed in accordance with certain aspects of the present invention. Adevice that operates using the energy detect with auto pair select statemachine 600 may begin initially in a standby state or in an awake state.For illustration, the situation where the device is in the standby stateis used.

[0038] When the device is in the standby state, the device waits until aqualified energy has been detected. As described above, the qualifiedenergy includes suppressing the energy associated with a transmittedlink pulse. After the qualified energy has been detected, then the stateof the energy detect with auto pair select state machine 600 moves to anenergy detect state. Then, the energy detect with auto pair select statemachine 600 waits a period of time, shown as timeout. This timeoutperiod may be programmed, predetermined, or adaptive based on theoperation of the device and the network in which the device isinstalled. If no more energy is received during the timeout period, thenthe state of the energy detect with auto pair select state machine 600reverts back to the standby state.

[0039] However, if energy is received and the qualified energy is stillhigh after that timeout period, then the state of the energy detect withauto pair select state machine 600 waits a period of time shown as timerto ensure that the qualified energy is at a high level. This again, ofcourse, involves suppressing the energy associated with any transmittedlink pulse during evaluation of the qualified energy. If the qualifiedenergy is still high indicating that link pulses are still coming in,then the state of the energy detect with auto pair select state machine600 changes to an awake state. Here, the device that employs the energydetect with auto pair select state machine 600 will remain indefinitelyuntil there is some indication that a link to another active device islost. For example, when it is detected that there is no more qualifiedenergy for a period of time (delta time), then the state of the energydetect with auto pair select state machine 600 will move to a no energystate for the length of period of a timer. The timer length here may bedifferent from the timer length associated with the energy detect state.Again, the length of this timer may be programmed, predetermined, oradaptive. This timer period may be 2-4 micro-seconds in one embodiment.Then, if the timer has passed indicating that there is no qualifiedenergy, the state of the energy detect with auto pair select statemachine 600 will pass back to the standby state, thereby permittingenergy savings once again.

[0040] One differentiating factor of the present invention, amongothers, when compared to any prior art system is the ability to utilizeboth transmit and receive pairs of a transceiver to be provided asinputs to a state machine such as the energy detect with auto pairselect state machine 600.

[0041] Any of the values of timeout, timers, and other parameters withinthe operation of the energy detect with auto pair select state machine600 may be programmed, predetermined, or adaptive. Those persons havingskill in the art will appreciate that the particular values used forthese types of operational parameters may be altered without departingfrom the scope and spirit of the invention.

[0042]FIG. 7 is a functional block diagram illustrating an embodiment ofan energy detect with auto pair select method 700 that is performed inaccordance with certain aspects of the present invention. In a block710, energy detect is performed on one or more twisted pairs. This mayinvolve performing energy detect on both the transmit and receive wirepairs, as shown in a block 712. Then, in a block 720, auto negotiationis performed. Auto negotiation is understood by those persons havingskill in the art, and it involves sending and receiving link pulses todetermine the capability of other devices in a network that areinterconnected. For example, there is a handshaking procedure in whichthe various devices may agree on a data communication rate at which bothor more devices are capable of communicating with each other. The periodassociated with auto negotiation is commonly on the order of severalmicro-seconds. It is noted that the energy detect with auto pair select,as described and performed in various embodiments, may be performedbefore the auto negotiation procedure, as it is important to determineat that time if there is in fact a partner to communicate with. Duringthe operation within the block 720, auto MDIX may be performed on one ormore twisted pairs, as necessary, as shown in a block 722.

[0043] Subsequently, in a block 730, the device is powered down whenthere is no energy detected. When appropriate, this energy is aqualified energy, accounting for and suppressing the energy that isassociated with any transmitted link pulses. In addition andalternatively, in a block 740, the device is subsequently awakened(powered up) when energy is later detected.

[0044] From certain perspectives, certain aspects of the energy detectwith auto pair select method 700 may be performed and described by theoperation of a state machine that implements and performs the methoddescribed within the FIG. 7.

[0045]FIG. 8 is a functional block diagram illustrating anotherembodiment of an energy detect with auto pair select method 800 that isperformed in accordance with certain aspects of the present invention.In a block 810, energy is sensed on one or more twisted pairs. Ifdesired, link pulses are simultaneously transmitted as shown in a block812. Then, in a block 820, the transmit link pulse energies aresubtracted from the summed energy to generate a qualified energy. Thisis performed when a link pulse is sent, regardless of whether or not avalid link has already been achieved. In this situation, the sensedenergy is transformed into a qualified energy where the energyassociated with the transmitted link pulse is suppressed. Thissuppression may be performed logically or actually, in variousembodiments without departing from the scope and spirit of theinvention.

[0046] Subsequently, in a block 830, the analysis of the operating stateis determined using the qualified energy. In a block 840, after there isknowledge of the connectivity and state of operation of the device(knowledge of any other link partner), auto negotiation can be performedif desired. Auto MDIX may be performed on one or more twisted pairgroups during auto negotiation, as necessary. Ultimately, the device ispowered down when there is no qualified energy detected, as shown in ablock 850. Alternatively, a partial power down may be performed on thedevice where some, but not all, of the functional components of thedevice are powered down to achieve power savings as shown in a block852.

[0047] In view of the above detailed description of the invention andassociated drawings, other modifications and variations will now becomeapparent to those skilled in the art. It should also be apparent thatsuch other modifications and variations may be effected withoutdeparting from the spirit and scope of the invention.

What is claimed is:
 1. An energy detect with auto pair select system,comprising: a device that is operable to perform energy detection withauto pair selection; a plurality of wire pairs that is communicativelycoupled to the device; and wherein the device generates a qualifiedenergy by considering an energy associated with at least two wire pairswithin the plurality of wire pairs; the device uses the qualified energyto determine whether at least one additional device is communicativelycoupled to the device via at least one wire pair within the plurality ofwire pairs; and the device performs auto power down when no device iscommunicatively coupled to the device via the wire pair.
 2. The energydetect with auto pair select system of claim 1, wherein the auto powerdown comprises a partial auto power down.
 3. The energy detect with autopair select system of claim 1, wherein the device performs auto mediadependent interface crossover functionality when the wire pair istransposed with at least one additional wire pair.
 4. The energy detectwith auto pair select system of claim 1, wherein the device subtracts alink pulse energy from the energy when the device transmits a link pulseto generate the qualified energy, the link pulse energy is associatedwith a link pulse that is transmitted from the device.
 5. The energydetect with auto pair select system of claim 4, further comprising an ORgate that sums energies on each of the plurality of wire pairs; and anAND gate that suppresses the link pulse energy from the sum of theenergies of each of the plurality of wire pairs.
 6. The energy detectwith auto pair select system of claim 1, wherein the device uses theenergy of at least one wire pair within the plurality of wire pairs asthe qualified energy when the device does not transmit a link pulse. 7.The energy detect with auto pair select system of claim 1, wherein theplurality of wire pairs comprises at least one of a receive wire pairand a transmit wire pair.
 8. The energy detect with auto pair selectsystem of claim 1, further comprising a state machine that is operableto determine connectivity of the device with the plurality of wirepairs.
 9. The energy detect with auto pair select system of claim 8,wherein the state machine is operable to change an operational state ofthe device based on whether at least one additional device iscommunicatively coupled to the device via at least one wire pair withinthe plurality of wire pairs.
 10. The energy detect with auto pair selectsystem of claim 1, wherein the device performs wake up from a standbystate when the device determines that the at least one additional deviceis communicatively coupled to the device via the wire pair.
 11. Anenergy detect with auto pair select system, comprising: a device that isoperable to perform energy detection with auto pair selection; a wirepair that is communicatively coupled to the device; and wherein thedevice determines whether the wire pair comprises an energy; the devicesubtracts a link pulse energy from the energy when the device transmitsa link pulse to generate a qualified energy, the link pulse energy isassociated with a link pulse that is transmitted from the device; thedevice uses the energy as the qualified energy when the device does nottransmit a link pulse; and the device uses the qualified energy todetermine whether at least one additional device is communicativelycoupled to the device via the wire pair.
 12. The energy detect with autopair select system of claim 11, wherein the device performs auto mediadependent interface crossover functionality when the wire pair istransposed with at least one additional wire pair.
 13. The energy detectwith auto pair select system of claim 12, wherein the device performsthe auto media dependent interface after determining whether the atleast one additional device is communicatively coupled to the device viathe wire pair.
 14. The energy detect with auto pair select system ofclaim 11, wherein the device performs auto power down when no device iscommunicatively coupled to the device via the wire pair.
 15. The energydetect with auto pair select system of claim 14, wherein the auto powerdown comprises a partial auto power down.
 16. The energy detect withauto pair select system of claim 11, wherein the device performs wake upfrom a standby state when the device determines that the at least oneadditional device is communicatively coupled to the device via the wirepair.
 17. The energy detect with auto pair select system of claim 11,wherein the device comprises a state machine that is operable to changean operational state of the device based on whether the at least oneadditional device is communicatively coupled to the device via the wirepair.
 18. The energy detect with auto pair select system of claim 11,further comprising at least one additional wire pair; and wherein thedevice sums energy on the wire pair and energy on the at least oneadditional wire pair.
 19. The energy detect with auto pair select systemof claim 18, wherein the wire pair comprises at least one of a transmitpair and a receive pair; and the at least one additional pair comprisesat least one of a transmit pair and a receive pair.
 20. An energy detectwith auto pair select system, comprising: a device that is operable toperform energy detection with auto pair selection; a plurality of wirepairs that is communicatively coupled to the device; a state machinethat is operable to determine connectivity of the device; and whereinthe device performs auto media dependent interface crossoverfunctionality when at least two wire pairs within the plurality of wirepairs are transposed; the device determines whether at least one wirepair within the wire pair comprises an energy; the device subtracts alink pulse energy from the energy, when the device transmits a linkpulse, to generate a qualified energy, the link pulse energy isassociated with a link pulse that is transmitted from the device; thedevice uses the energy as the qualified energy when the device does nottransmit a link pulse; the device provides the qualified energy to thestate machine; the state machine determine whether at least oneadditional device is communicatively coupled to the device via the wirepair; and the device performs energy savings management.
 21. The energydetect with auto pair select system of claim 20, wherein the statemachine is contained within the device.
 22. The energy detect with autopair select system of claim 20, wherein the device is operable within atleast one of a standby state and an awake state as determined by thestate machine.
 23. The energy detect with auto pair select system ofclaim 20, wherein the device performs auto power down when the devicedetermines that no device is communicatively coupled to the device viathe wire pair.
 24. The energy detect with auto pair select system ofclaim 20, further comprising an OR gate that sums energies on each ofthe plurality of wire pairs; and an AND gate that suppresses the linkpulse energy from the sum of the energies of each of the plurality ofwire pairs.
 25. An energy detect with auto pair select method, themethod comprising: performing energy detection of a plurality of wirepairs, at least one wire pair within the plurality of wire pairs iscommunicatively coupled to a device; generating a qualified energy byconsidering an energy associated with at least two wire pairs within theplurality of wire pairs; determining whether at least one additionaldevice is communicatively coupled to the device via at least one wirepair within the plurality of wire pairs; and performing auto power downwhen no device is communicatively coupled to the device via the wirepair.
 26. The method of claim 25, further comprising performing autonegotiation between the device and at least one additional device. 27.The method of claim 25, further comprising waking up the device from astandby state.
 28. The method of claim 25, wherein the auto power downcomprises a partial auto power down.
 29. The method of claim 25, furthercomprising performing auto media dependent interface crossoverfunctionality when the wire pair is transposed with at least oneadditional wire pair.
 30. The method of claim 25, further comprisingsumming energies on each of the plurality of wire pairs; and suppressingenergy associated with a transmitted link pulse from the sum of theenergies of each of the plurality of wire pairs, the transmitted linkpulse being transmitted from a device.
 31. The method of claim 25,further comprising using the energy of at least one wire pair within theplurality of wire pairs as the qualified energy when the device does nottransmit a link pulse.
 32. The method of claim 25, wherein the pluralityof wire pairs comprises at least one of a receive wire pair and atransmit wire pair.
 33. The method of claim 25, further comprisingemploying a state machine to determine connectivity of the device withthe plurality of wire pairs.
 34. The method of claim 33, wherein thestate machine is operable to change an operational state of the devicebased on whether at least one additional device is communicativelycoupled to the device via at least one wire pair within the plurality ofwire pairs.
 35. The method of claim 25, wherein the device performs wakeup from a standby state when the device determines that the at least oneadditional device is communicatively coupled to the device via the wirepair.
 36. An energy detect with auto pair select method, the methodcomprising: performing energy detection with auto pair selection on adevice having a wire pair communicatively coupled thereto; determiningwhether the wire pair comprises an energy; subtracting a link pulseenergy from the energy, when the device transmits a link pulse, togenerate a qualified energy, the link pulse energy is associated with alink pulse that is transmitted from the device; using the energy as thequalified energy when the device does not transmit a link pulse; andusing the qualified energy to determine whether at least one additionaldevice is communicatively coupled to the device via the wire pair. 37.The method of claim 36, further comprising performing auto mediadependent interface crossover functionality when the wire pair istransposed with at least one additional wire pair.
 38. The method ofclaim 37, further comprising performing the auto media dependentinterface after determining whether the at least one additional deviceis communicatively coupled to the device via the wire pair.
 39. Themethod of claim 36, further comprising performing auto power down whenno device is communicatively coupled to the device via the wire pair.40. The method of claim 39, wherein the auto power down comprises apartial auto power down.
 41. The method of claim 36, further comprisingwaking up the device from a standby state after determining that the atleast one additional device is communicatively coupled to the device viathe wire pair.
 42. The method of claim 36, further comprising employinga state machine to change an operational state of the device based onwhether the at least one additional device is communicatively coupled tothe device via the wire pair.
 43. The method of claim 36, wherein atleast one additional wire pair is communicatively coupled to the device;and further comprising summing energy on the wire pair and energy on theat least one additional wire pair.
 44. The method of claim 43, whereinthe wire pair comprises at least one of a transmit pair and a receivepair; and the at least one additional pair comprises at least one of atransmit pair and a receive pair.